EP0056172B1

EP0056172B1 - Phenoxy- and thiophenoxy compounds, methods for their preparation and pharmaceutical formulations containing them

Info

Publication number: EP0056172B1
Application number: EP81201386A
Authority: EP
Inventors: David Norman Hardern; Thomas Brian Lee; John Raymond Bantick
Original assignee: Fisons Ltd
Current assignee: Fisons Ltd
Priority date: 1981-01-09
Filing date: 1981-12-18
Publication date: 1985-04-03
Also published as: EP0056172A3; FI820017L; AU7920382A; DE3169761D1; DK2182A; EP0056172A2; NO820035L

Description

This invention concerns new compounds, processes for their preparation and compositions containing them.
According to the invention we provide compounds of formula I,
in which R is a group of formula II,

R¹, R² and R³, which may be the same or different each represent hydrogen, alkyl, alkenyl, alkenyloxy, halogen, alkoxy, alkanoyl or hydroxy,
one or more of R⁴, R⁵ and R⁶ represents alkyl, alkanoyl, alkenyl, ―COOH or ―ACOOH where A represents Y, OY or SY and Y represents a -CH=CH-, methylene, ethylene or 1,3-propylene chain, and the remainder of R⁴, R⁵ and R⁶ represent hydrogen,
X represents a hydrocarbon chain having from 2 to 7 carbon atoms optionally substituted by hydroxy,
E represents -S-, ―O―, or ―CH₂―, and
G represents ―S― or ―O―,

a) when R¹ and R²are hydrogen R³does not represent chlorine, isopropyl or t-butyl and is not para to E, or
b) when E and G are both ―O―, either
- i) the R group is not of formula III,
  in which
  - R⁷ is hydrogen or alkyl,
  - R⁸ is alkanoyl, and
  - R⁹ is alkyl or alkenyl,
  when only one of R⁴, R⁵ and R⁶ represent a group -COOH, -Y-COOH or -OYCOOH, or
  when one of R⁴, R⁵ and R⁶ represent a group ―COOH, ―Y―COOH or―OYCOOH and another of R⁴, R⁵ and R⁶ represents ―COOH, or
- ii) two or more of R⁴, R⁵ and R⁶ represent ―ACOOH, or
- iii) at least one or R⁴, R⁵ and R⁶ represents a group ―SYCOOH, or
- iv) none of R⁴, R⁵ and R⁶ represents a group selected from ―COOH and―ACOOH,
c) when one of R⁴,R⁵ and R⁶ represents―COOH,―CH₂COOH,―(CH₂)₂ COOH or―(CH₂)₃ COOH para to G, another of R⁴, R⁵ and R⁶ is hydrogen or alkyl, the third of R⁴, R⁵ and R⁶is hydrogen, R¹ and R² are selected from hydrogen, alkyl, alkoxy and halogen, and R³ is other than hydrogen, then X carries a hydroxy substituent, or
d) when R⁴ represents―OCH₂ COOH, R⁵ and R⁶ are both hydrogen, R¹ is hydrogen and R² and R³ are selected from alkyl, alkoxy and halogen, then X carries a hydroxy substituent,

The invention also provides the compounds of formula I and pharmaceutically acceptable derivatives thereof, as pharmaceuticals.
According to the invention we also provide a process for the preparation of a compound of formula I or a pharmaceutically acceptable derivative thereof, which comprises,

(a) producing a compound of formula I in which one or more of R⁴, R⁵and R⁶ represents -COOH or -ACOOH, by selective hydrolysis of a compound of formula IV,
in which R, E, X and G are as defined above,
one or more of D⁴, D⁵ and D⁶ represent a group hydrolysable to -COOH, or to -ACOOH, and the remainder of D⁴, D⁵ and D⁶ represent groups R⁴, R⁵ and R⁶ as defined above,
(b) reacting a compound of formula REZ with a compound of formula V or an ester thereof,
in which
- R, E, G, R⁴, R⁵ and R⁶ are as defined above, and
- L and Z represent the pair of groups (i) hydrogen or a reactive metal, and (ii) a hydrocarbon chain having from 2 to 7 carbon atoms and carrying an anion forming group or an epoxide group,
(c) producing a compound of formula I in which one or more of R¹ to R⁶ represent an alkyl group containing at least 2 carbon atoms and/or A represents an ethylene chain, by hydrogenation of a compound of formula I wherein one or more of R¹ to R⁶ represents an alkenyl or alkanoyl group, and/or A represents -CH=CH-,
(d) producing a compound of formula I in which one or more of R⁴, R⁵ and R⁶ represent -ACOOH where A represents a group OY or SY, by reacting a corresponding compound of formula I in which either an adjacent pair of R¹, R² and R³ represent―OH and an alkanoyl group, or none of R¹, R² and R³ represents a non-hydrogen-bonded hydroxyl group and one of R⁴, R⁵ and R⁶ represents an ―OH or―SH group, with an appropriate haloalkanoic acid derivative in the presence of a suitable base,
e) production of a compound of formula I in which at least one of R¹, R² and R³ represents alkenyloxy or alkoxy, by alkenylating or alkylating a corresponding compound of formula I in which at least one of R¹, R² and R³ represents hydroxy,
f) production of a compound of formula I, or an ester thereof, in which at least one of R¹, R² and R³ represents―OH and another of R¹, R² and R³ represents an allyl group or an allyl group substituted by alkyl in the position adjacent to the benzene ring, by subjecting to an elevated temperature a corresponding compound of formula I, or an ester therefore, in which at least one of R¹, R² and R³ represents hydrogen and another of R¹, R² and R³ represents an allyloxy group or an alkyl substituted allyloxy group, or
g) converting an acid of formula I to a pharmaceutically acceptable derivative thereof or vice versa.

In process (a) the groups D⁴, D⁵ and D⁶ may, for example, be carboxylic amide, nitrile or preferably ester, e.g. lower alkyl ester, groups, which may be hydrolysed to a -COOH or -ACOOH group. The hydrolysis may be carried out using conventional techniques, for example, under mildly basic conditions, e.g. using sodium bicarbonate. The reaction is preferably carried out at a temperature of 20° to 120°C.
In process (b) when L or Z is a reactive metal the metal may, for example, be an alkali metal, e.g. sodium, or another reactive metal, e.g. thallium. When L or Z represents a hydrocarbon chain carrying an anion forming group the anion forming group may be, for example, a halogen atom, e.g. bromine, or a sulphonate group, e.g. a methyl sulphonate or a p-toluenesulphonate group. When L or Z represents a hydrocarbon chain carrying a halogen atom the reaction may be carried out in the presence of a solvent which is inert under the reaction conditions, e.g. acetone and in the presence of an acid acceptor, e.g. potassium carbonate. The reaction is also preferably carried out under anhydrous conditions and in the presence of a suitable catalyst, e.g. KI. When L or Z represents a hydrocarbon group carrying an epoxide group the reaction may be carried out at an elevated temperature in a solvent which is inert under the reaction conditions, e.g. dioxan or dimethylformamide, and in the presence of a suitable catalyst, e.g. trimethylbenzylammonium- hydroxide. Alternatively the reaction may be carried out in the presence of a tertiary alcohol, e.g. t-butanol or 1,1-dimethyl-propan-1-01 and in the presence of the potassium salt of the alcohol as catalyst.
In process (c), hydrogenation may be effected by conventional procedures, e.g. the use of hydrogen in the presence of Raney nickel, or palladium catalyst dispersed on an inert support. The reaction is preferably carried out at a temperature of from about 20 to 80°C.
Process (d) may be conveniently effected in an appropriate solvent medium, e.g. acetone or dimethylformamide. Where one or more of R⁴, R⁵ and R⁶ represent mercapto, the solvent medium may advantageously be water. The base employed is preferably an alkali-metal base, e.g. potassium carbonate or sodium hydride.
Process (e) may be carried out using, an alkenylating or alkylating agent, an alkenyl or alkyl group linked to a good leaving group, e.g. an alkenyl- or alkyl- halide. The reaction may be carried out in a solvent which is inert under the reaction conditions, e.g. dimethyl formamide, and in the presence of a base e.g. K₂C0₃ or NaH. The reaction is preferably carried out at a temperature of from 20° to 120°C.
In process f) the reaction may be carried out under conditions conventional for a Claisen rearrangement, e.g. at a temperature of from about 120° to 250°C optionally in a high boiling solvent which is inert under the reaction conditions, e.g. N-methylpyrrolidinone.
In process (g), the techniques involved are conventional, including treatment of a compound of formula I which contains an acidic group or a salt thereof with an appropriate base, e.g. a sodium base, or with an appropriate salt by a metathetical process.
The starting materials for the above processes are either known or may be made from known starting materials in a manner known for the production of similar known compounds.
The processes as described above may produce the compound of formula I or a derivative thereof. It is also within the scope of this invention to treat any derivative so produced to liberate the free compound of formula I, or to convert one derivative into another.
The compounds of formula I and the intermediates therefore may be isolated from their reaction mixtures using conventional techniques.
Pharmaceutically acceptable derivatives of the compounds of formula I include pharmaceutically acceptable salts, esters and amides of any -COOH group present. Suitable salts include ammonium, alkali metal (e.g. sodium, potassium and lithium) and alkaline earth metal (e.g. calcium or magnesium) salts, and salts with suitable organic bases, e.g. salts with hydroxylamine, lower alkylamines such as methylamine or ethylamine, with substituted lower alkylamines, e.g. hydroxy substituted alkylamines such as tris(hydroxymethyl)methylamine, with simple monocyclic nitrogen heterocyclic compounds. e.g. piperidine or morpholine, with an amino acid, e.g. lysine, ornithine, arginine, or an N-alkyl, especially an N-methyl derivative of any one thereof, or with an aminosugar, e.g. glucamine, N-methylglucamine or glucosamine. Suitable esters include simple lower alkyl esters, e.g. the ethyl ester, esters derived from alcohols containing basic groups, e.g. di-lower alkyl amino substituted alkanols such as the 2-(diethylamino)-ethyl ester, and acyloxy alkyl esters, e.g. a lower acyloxy-lower alkyl ester such as the pivaloyloxymethyl ester. The pharmaceutically acceptable acid addition salts of the basic esters, e.g. the hydrochloride, the hydrobromide, the maleate or the fumarate salts, may also be used. The esters may be made by conventional techniques, e.g. esterification or transesterification. The amides may be, for example, unsubstituted or mono- or di- C 1 to 6 alkyl or phenyl amides and may be made by conventional techniques, e.g. reaction of an ester of the corresponding acid with ammonia or an appropriate amine. Other pharmaceutically acceptable derivatives are compounds which will be suitable bioprecursors (prodrugs) of the compounds of formula I and will be readily apparent to those skilled in the art and may be made from the compounds of formula I using conventional processes known perse or by processes analogous to those described above.
The compounds of formula I and their pharmaceutically acceptable derivatives possess pharmacological properties. In particular, they are antagonists of the slow reacting substance of anaphylaxis (SRS-a) or its pathological effects, as indicated by their activity in the test described by Augstein et al, Nature New Biology, 1973, 245, 215.
The compounds are thus indicated for use in the treatment of disorders in which SRS-A is a factor, for example skin afflictions, hay fever and obstructive airways diseases, e.g. asthma, bronchitis and bronchorrhea.
For the above mentioned uses, the dosage administered will, of course, vary depending upon the compound employed, mode of administration and treatment desired. However, in general satisfactory results are obtained when administered at a daily dosage of from about 0.05 milligrams to about 10 milligrams per kilogram of animal body weight, preferably given in divided doses 2 to 4 times a day or in substained release form. For the larger mammals, the total daily dosage is in the range of from about 1 - milligram to about 700 milligrams and dosage forms suitable for administration comprise from about 12 milligrams to about 350 milligrams of the compound admixed with a solid or liquid pharmaceutical carrier or diluent. The compounds may be administered during or before the attack of the disorder to be treated.
The compounds of formula I and the pharmaceutically acceptable derivatives thereof, are more active, more stable, more selective, less toxic or possess less side effects when tested in certain pharmacological models, are more potent, have a different (e.g. longer) duration of action, have a different absorption profile (e.g. are better absorbed), are more easily formulated or possess other advantageous properties when compared to similar known compounds.
According to our invention we also provide a pharmaceutical composition comprising (preferably a minor proportion of) a compound of formula I, or a pharmaceutically acceptable derivatives thereof, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier. Examples of suitable adjuvants, diluents or carriers are:―for tablets and dragées; lactose, starch, talc or stearic acid; for capsules, tartaric acid or lactose; for suppositories, natural or hardened oils or waxes; for inhalation a coarse carrier, e.g. lactose or a compressed gas propellant, e.g. a chlorofluorohydrocarbon, and optionally a surfactant; and for topical application, wool fat, soft paraffin or a cream BP. For use in such compositions, the compound of formula I, or the pharmaceutically acceptable derivative thereof, preferably has a mass median diameter of from 0.01 to 10 microns. The compositions may also contain suitable preserving, stabilising and wetting agents, solubilizers, sweetening and colouring agents and flavourings. The compositions may, if desired, be formulated in sustained release form. We prefer compositions which are designed to be administered by inhalation.
The groups R¹ to R⁶, when they contain carbon, preferably contain less than 7 carbon atoms.
The alkyl groups which R¹ to R⁶ may represent preferably contain from 1 to 4 carbon atoms, a particularly preferred group being n-propyl.
The alkenyl groups which R¹ to R⁶ may represent preferably contain from 2 to 4 carbon atoms, a particularly preferred group being allyl.
We prefer R¹ to R³, when halogen, to be chlorine.
When one or more of R¹, R² and R³ represents an alkanoyl group it is preferably a C 2 to 6 alkanoyl group, e.g. acetyl.
Preferably, at least one (and preferably only one) of R⁴, R⁵ and R⁶ represents―COOH or―ACOOH. A particularly preferred group-ACOOH is-OCH₂COOH. The-COOH or-ACOOH group is preferably para to the group G.
Where one or more of R¹ to R⁶ represent an alkyl group, it is preferably ortho to the―EXG―chain.
X preferably represents a straight chain saturated hydrocarbon group, a particularly preferred group being trimethylene or 2-hydroxytrimethylene.
'We prefer E and G both to be oxygen or one to be oxygen and the other sulphur.
A preferred group of compounds of formula I are those in which E and G are both oxygen, one or more of R¹, R² and R³ represent alkyl, alkenyl, alkoxy, alkanoyl or hydroxy and the remainder each represent hydrogen, and X, R⁴, R⁵ and R⁶ are as defined above save that Y does not represent―CH=CH―.
A further preferred group of compounds of formula I are those in which E and G are both oxygen, R¹ represents alkanoyl C 2 to 4, R³ is -OH, R⁴ is ortho to G, R² and R⁴, which may be the same or different, each represent alkyl C 1 to 4, R⁵ is hydrogen and R⁶ represents carboxy,-YCOOH or-OYCOOH in which Y does not represent―CH=CH―. In this preferred group we further prefer R¹ to be acetyl, R²to be n-propyl, R⁴ to be n-propyl and R⁶ to be―OCH₂COOH.
A still further preferred group of compounds of formula I are those in which proviso b) i) reads:-

i) the R group is not of formula Illa,
in which
- R¹⁰ and R" are selected from hydrogen, halogen or alkyl
- R¹² is alkanoyl,
- R¹³ is hydrogen or hydroxy, and
- R¹⁴ is alkyl or alkenyl,
- when only one of R⁴, R⁵ and R⁶ represent -COOH, -Y-COOH or -OYCOOH, or
- when one of R⁴, R⁵ and R⁶ represent a group ―COOH, ―Y―COOH or ―OYCOOH and another of R⁴, R⁵ and R⁶ represents―COOH.

A specifically preferred group of compounds are those of formula la,
in which

M is hydrogen or -OH
A^a is -SCH₂COOH, -CH=CHCOOH or -CH₂CH₂COOH, and
E^a is ―O―when A^a is ―SCH₂COOH or ―S― when A^a is ―CH=CHCOOH or ―CH₂CH₂COOH.

Certain of the compounds of formula I possess one or more chiral centres and the invention also provides the compounds in the form of their individual optical isomers or as racemic, or other, mixtures thereof. Certain of the compounds of formula I may also exist as cis or trans isomers and in these cases the invention provides both isomeric forms. The various isomers may be prepared and/or separated using conventional processes known per se.
The invention is illustrated, but in no way limited, by the following Examples.

Example 1

Sodium trans-3-(4-[3-(2-allyl-4-acetylphenoxy)propyloxy]phenyl]propenoate

(a) Methyl trans 3-(4-[3-bromopropyloxy]phenyl) propenoate

To a suspension of potassium carbonate (21.7 g) and 1,3-dibromopropane (145 mls) in refluxing acetone (350 mls) was added dropwise over 48 h a solution of methyl trans-4-hydroxycinnamate (25.5 g) in acetone (50 mls). The reaction mixture was allowed to cool, the potassium carbonate was removed by filtration and the solvent was evaporated. The residue was triturated with petroleum ether (bp 40-60) to afford the sub-title compound (34.6 g) mp 76-78°C.

(b) Methyl trans-3-(4-[3-(2-allyl-4-acetylphenoxy)propyloxy]phenyl)propenoate

A mixture of 2-allyl-4-acetyl-phenol (3.23 g) and methyl trans-3-(4-[3-bromopropyloxy]phenyl)-propenoate (5 g) in dry N,N-dimethylformamide (50 mls) containing potassium carbonate (2.54 g) was stirred for 72 hours, poured into water, and extracted with ethyl acetate. The organic solution was washed with water, dried, and evaporated to give a colourless oil which solidified on trituration with petroleum ether (bp 40-60). The crude product was purified by chromatography over silica gel to give the sub-title compound (4.67 g) mp 80-81°C.

(c) Trans-3-(4-[3-(2-allyl-4-acetylphenoxy)propyloxy]phenyl)propenoic acid

To a solution of the product of step b) (2 g) in dioxan (30 mls) was added 1 N sodium hydroxide solution (10.16 mls) and stirring was continued for 16 hours. The solution was evaporated, the residue was dissolved in water, acidified to pH 1 and extracted with ethyl acetate. The organic solution was dried and evaporated to give a solid which was recrystallised from ethyl acetate to give the sub-title compound (1.1 g) M.pt 165-165.5°C.

(d) Sodium trans-3-(4-[3-(2-allyl-4-acetylphenoxy)propyloxy]phenyl)propenoate

The product of step c) and an equivalent amount of sodium bicarbonate were dissolved together in water and the resulting solution was freeze-dried to afford the sub-title sodium salt.

Example 2

Sodium 3-[4-(3-[2-acetyl-3-hydroxyphenoxy]propyloxy)phenyl]propanoate

Methyl trans - 3 - [4 - (3 - [2 - acetyl - 3 - hydroxyphenoxy]propyloxy)phenyl]propenoate (1 g) in acetone (50 ml) was hydrogenated over 10% palladium on charcoal for 4 hours at atmospheric pressure. Evaporation of the solvent gave methyl 3 - [4 - (3 - [2 - acetyl - 3 - hydroxyphenoxy]propyloxy)phenyl]-propanoate (0.96 g) as an oil, characterised by 'HNMR and MS.
The oil was hydrolysed by the method in Example I (c) to give the acid of the title salt (0.62 g), mp 134-135°.
The title solid salt was prepared from the acid by the method of Example 1 (d).

Example 3

Sodium (4-[3-(4.acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenylthio)acetate

(a) Ethyl (4-(3-(4-acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenylthio)acetate

Ethyl (4-hydroxyphenylthio) acetate (1.5 g), potassium carbonate (1.0 g), 1 - [4 - (3 - bromo- propyloxy) - 2 - hydroxy - 3 - propyiphenyllethanone (2.25 g) and potassium iodide (0.1 g) in dry dimethylformamide (20 mls) were heated to 80°C and stirred for 18 hours under a nitrogen atmosphere. The mixture was poured into dilute (5%) hydrochloric acid and extracted with ethyl acetate which was washed with water, dried and evaporated. The resulting oil was chromatographed on silica gel using dichloromethane as eluant to give the sub-title compound as a pale yellow oil (2.3 g).
The structure was confirmed by 'H NMR and M.S.

(b) (4-[3-(4Acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenylthio)acetic acid

The product of step a) (2.2 g) in ethanol (25 mls) and sodium carbonate (1.5 g) in water (5 mls) were refluxed for one hour, with occasional addition of water. The mixture was poured into excess dilute hydrochloric acid and extracted into ethyl acetate, which was washed with water, dried, and evaporated to an oil. Crystallisation of the oil from ether/petroleum ether (bp 40-60) (1:3) gave the sub-title compound (0.7 g) mpt 93-94°C.

(c) Sodium (4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)propoxy]phenylthio)acetate

The product of step b) (0.6 g) was dissolved in ethanol (8 mls) and treated with an equivalent amount of 1 N sodium hydroxide solution. The solvents were evaporated and the residue was dissolved in a minimum of water, filtered and freeze-dried to give the title sodium salt.

Example 4

Sodium (4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)-2-hydroxypropoxy]phenylthio)acetate

(a) Ethyl 4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy)-2-hydroxypropoxy]phenylthio)acetate

Ethyl (4-hydroxyphenylthio)acetate (2.3 g), 1 - [4 - (2,3 - epoxypropoxy) - 2 - hydroxy - 3 - propylphenyl]ethanone (4.0 g) and benzyl trimethylammonium hydroxide (40%; 0.15 mls) in dry dimethylformamide (20 mls) were heated to 130°C for 10 hours under a nitrogen atmosphere. The mixture was poured into dilute hydrochloric acid and extracted into ethyl acetate, was washed with water, dried and evaporated to give a brown oil. Chromatography on silica gel with dichloromethane containing ethyl acetate (8%) gave the sub-title compound (2.1 g) as an oil. The structure was confirmed by 'H NMR and M.S.

(b) Sodium (4-[3-(4-acetyl-3-hydroxy-2-propylphenoxy-2-hydroxypropoxy]phenylthio)acetate

Hydrolysis of the product of step a) by the method of Example 3 b) gave (4 - [3 - (4 - acetyl - 3 - hydroxy - 2 - propylphenoxy - 2 - hydroxypropoxy]phenylthio)acetic acid, mp 95-96°.
The title salt was prepared by the method of Example 3 c).

Example 5

Sodium trans-3-(4-[3-(2-acetyl-3-allyloxyphenoxy)propyloxy]phenyl)propenoate

(a) Methyl trans-3-(4-[3-(2-acetyl-3-allyloxyphenoxy)propyloxy)phenyl)propenoate

A mixture of methyl trans - 3 - (4 - [3 - (2 - acetyl - 3 - hydroxyphenoxy)propyloxy]phenyl)-propenoate (4 g), dry N,N-dimethylformamide (30 mls), potassium carbonate (3.0 g), and allyl bromide (1.88 mls) was stirred for 16 hours. The mixture was poured into water and extracted with ethyl acetate. The extracts were washed with water, dried and evaporated to give the sub title compound (4.27 g), mp 73-75°C.

(b) Sodium trans-3-(4-[3-(2-acetyl-3-allyloxyphenoxy)propyloxy]phenyl)propenoate

Methyl trans - 3 - (4 - [3 - (2 - acetyl - 3 - allyloxyphenoxy)propyloxy]phenyl)propenoate was hydrolysed by the process of Example 1 c) to give the corresponding acid, mp 151-2°. The title salt was prepared by the process of Example 1 d).

Example 6

Sodium trans-3-(4-(3-[2-acetyl-4-allyl-3-hydroxyphenoxy)propyloxy]phenyl)propenoate

(a) Methyl trans-3-(4-(3-[2-acetyl-4-allyl-3-hydroxyphenoxy)propyloxy]phenyl)propenoate

Methyl trans - 3 - (4 - [3 - (2 - acetyl - 3 - allyloxyphenoxy)propyloxy]phenyl)propenoate (2 g) in N-methylpyrrolidinone (20 mls) was refluxed under a nitrogen atmosphere for 5 hours. The solution was poured into water and extracted with ethyl acetate. The extracts were dried, and evaporated to give an oil which was chromatographed on silica to give the sub-title ester (1.05 g) mp 99-100.5°.

(b) Sodium trans-3-(4-(3-[2-acety-4-allyl-3-hydroxyphenoxy)propyloxy]phenyl)propenoate

The product of step a) was hydrolysed by the process of Example 1 c) to give the corresponding acid, m p. 175-6°.
The title salt was prepared by the process of Example 1 d).

Example 7

By the methods of Examples 1 b), c) and d) and using appropriate starting materials were prepared the following acids and their sodium salts:-

(a) Trans-3-(4-(3-[2-propylphenoxy]propyloxy)phenyl)propenoic acid, mp 110―111°.
(b) Trans-3-(4-(3-[2-acetyl-3-hydroxyphenoxy]propyloxy)phenyl)propenoic acid, mp 239-240°.
(c) Trans 3-(4-(3-[4-acetyl-3-hydroxy-2-propylphenylthio]propyloxy)phenyl)propenoic acid, m.p. 152.5-153.5°.
(d) Trans 3-[4-(3-[3-acetyl-4-hydroxy-5-propylphenoxy]propyloxy)phenyl]propenoic acid, oil characterised by 'HNMR and MS.

Example 8

By the methods of Examples 2 and 1 d) using appropriate starting materials the following acid and its sodium salt were prepared:-

(a) 3-(4-(3-[4-Acetyl-3-hydroxy-2-propylphenythio]propyloxy)phenyl)propanoic acid, mp. 96―97°.

Example 9

By the methods of Examples 3 a), 3 b) and 1 d) using appropriate starting materials the following acids and their sodium salts were prepared:-

a) 3-[4-(5-(2-Acetyl-3-hydroxyphenoxy)pentyloxy)-3,5-diallylphenyl]propanoic acid, oil.
b) (4-[3-(4-Acetyl-6-bromo-3-hydroxy-2-propylphenoxy)propoxylphenylthio)acetic acid, m.p. 109-110°.

Example 10

Sodium 6-acetyl-3-(5-phenylpentylthio)-2-propylphenoxy acetate

a) 2-Hydro-4-(5-phenylpentylthio)-3-propylacetophenone

5-Bromopentylbenzene (1.93 g), 2-hydroxy-4-mercapto-3-propylacetophenone (1.78 g), potassium carbonate (1.28 g) and dimethylformamide (60 ml) containing potassium iodide (0.1 g) were stirred at 60° under nitrogen for 20 hours, poured into dilute hydrochloric acid and extracted with ethyl acetate. The organic phase was washed with water, dried and evaporated to yield an oil which was chromatographed over silica gel with petroleum ether (bp 40-60) containing ether (10%) to give the sub-title compound (1.85 g), mp 82-83°.

b) Sodium 6-acetyl-3-(5-phenylpentylthiol)-2-propylphenoxyacetate

The product of step a) (0.67 g) in dry dimethylformamide (5 ml) was slowly added to stirred suspension of sodium hydride (0.09 g) in dimethylformamide (25 ml).
The solution was warmed to 35° for 0.5 hours, then cooled to 10° and treated with ethyl chloroacetate (0.2 ml). After 14 hours at room temperature the mixture was poured into dilute hydrochloric acid and extracted with ethyl acetate, which was then washed with water, dried and evaporated to an oil. Chromatography over silica with light petroleum ether (bp 40-60) containing ether (20%) gave the ester of the title compound as an oil (0.15 g). This ester was hydrolysed by the method of Example 3 b) to give, (after crystallisation from light petroleum ether (bp 40-60) containing ether), 6 - acetyl - 3 - (5 - phenylpentylthio) - 2 - propylphenoxyacetic acid (0.8 g), mp 117-118⁰.
The title sodium salt was prepared by the method of Example 3 c).

Example 11

Preparation of novel intermediates

a) Methyl 3-[3,5-diallyl-4-hydroxyphenyl]propanoate

Methyl 3-(4-allyloxyphenyl)propanoate (24.5 g) was refluxed in N-methylpyrrolidinone (100 ml) under nitrogen for 5 hours, and then poured into water. Extraction with ethyl acetate and evaporation afforded methyl 3-(3-allyl-4-hydroxyphenyl)propanoate as an oil (24.5 g), characterised by 'HNMR and MS. This oil, allyl bromide (13,3 g), and potassium carbonate (16.7 g) were heated with stirring in dimethylformamide (100 ml) at 70° under N2 for 15 hours. The mixture was treated with dilute hydrochloric acid and extracted with ethyl acetate, which was then washed with 5% sodium carbonate solution, and water. Evaporation gave methyl 3-(3-allyl-4-allyloxyphenyl)propanoate as an oil (14.8 g), characterised by 'HNMR and MS. This oil was refluxed in N-methylpyrrolidinone (80 ml) for 5 hours under nitrogen, cooled, poured into water and extracted with ethyl acetate. Evaporation furnished the title compound as an oil (12.3 g), characterised by 'H NMR and MS.

b) 5-Bromo-4-(3-bromopropoxy)-2-hydroxy-3-propylacetophenone

To 4-(3-bromopropoxy)-2-hydroxy-3-propylacetophenone (15.8 g) in glacial acetic acid (40 ml) and chloroform (20 ml) at 0° was added dropwise with stirring a solution of bromine (2.58 ml) in acetic acid (20 ml). After 10 minutes the mixture was poured into dilute sodium bisulphite solution and extracted with methylene chloride, which was washed with water, dried and evaporated to an oil. Chromatography over silica gel with petroleum ether (bp 60-80) containing ether (5%) gave the sub-title compound as an oil (12 g), characterised by 'HNMR and MS.

c) 2,5-dihydroxy-3-propylacetophenone

5-Benzyloxy-2-hydroxyacetophenone (75.4 g), allyl bromide (41.2 g) and potassium carbonate (46.9 g) were refluxed in dimethylformamide (200 ml) for 3 hours with stirring. The mixture was poured onto ice and extracted with ether, which was then washed with 5% sodium hydroxide, and water, dried and evaporated. The residue was extracted repeatedly with hot light petroleum ether (bp 40-60). The combined extracts were concentrated, and on cooling afforded 2-allyloxy-5-benzyloxyacetophenone (29.9 g) mp 48-52°. This solid was refluxed in dimethylaniline (100 ml) under nitrogen for 11 hours, cooled, poured into dilute hydrochloric acid and extracted with ether. To the organic layer was added 20% sodium hydroxide solution (50 ml). The precipitated salt was collected, washed well with ether, and treated with dilute hydrochloric acid. Extraction and evaporation gave 3-allyl-5-benzyloxy-2-hydroxyacetophenone (22 g) as a solid. This solid in ethanol containing a little dilute hydrochloric acid was hydrogenated at 4 atmospheres and 60° over 5% palladium on charcoal for 16 hours. Evaporation of the solvent gave the sub-title compound (13 g), mp 92-93^0.

Claims

1. A process for the production of a compound of formula I,

in which

R is a group of formula II,

R', R² and R³, which may be the same or different each represent hydrogen, alkyl, alkenyl, alkenyloxy, halogen, alkoxy, alkanoyl or hydroxy,

one or more of R⁴, R⁵ and R⁶ represents alkyl, alkanoyl, alkenyl, ―COOH or ―ACOOH where A represents Y, OY or SY and Y represents a -CH=CH-, methylene, ethylene or 1,3-propylene chain, and the remainder of R⁴, R⁵ and R⁶ represent hydrogen,

X represents a hydrocarbon chain having from 2 to 7 carbon atoms optionally substituted by hydroxy,

E represents ―S―, ―O― or ―CH₂―, and

G represents -S- or -0-,

provided that

a) when R¹ and R² are hydrogen R³ does not represent chlorine, isopropyl or t-butyl and is not para to E, or

b) when E and G are both -0-, either

i) the R group is not of formula III,

in which

R⁷ is hydrogen or alkyl,

R⁸ is alkanoyl, and

R⁹ is alkyl or alkenyl,

when only one of R⁴, R⁵ and R⁶ represent a group -COOH, -Y-COOH or -OYCOOH, or
when one of R⁴, R⁵ and R⁶ represent a group―COOH,―Y―COOH or―OYCOOH and another of R⁴, R⁵ and R⁶ represents -COOH, or

ii) two or more of R⁴, R⁵ and R⁶ represent ―ACOOH, or

iii) at least one of R⁴, R⁵ and R⁶ represents a group ―SYCOOH, or

iv) none of R⁴, R⁵ and R⁶ represents a group selected from ―COOH and ―ACOOH,

c) when one of R⁴, R⁵ and R⁶ represents ―COOH, ―CH₂COOH, ―(CH₂)₂ COOH or―(CH₂)₃ COOH para to G, another of R⁴, R⁵ and R⁶ is hydrogen or alkyl, the third of R⁴, R⁵ and R⁶ is hydrogen, R¹ and R² are selected from hydrogen, alkyl, alkoxy and halogen, and R³ is other than hydrogen, then X carries a hydroxy substituent, or

d) when R⁴ represents ―OCH₂ COOH, R⁵ and R⁶ are both hydrogen, R¹ is hydrogen and R² and R³ are selected from alkyl, alkoxy and halogen, then X carries a hydroxy substituent,

or a pharmaceutically acceptable derivative of those compounds containing an acidic function, which comprises

(a) producing a compound of formula I in which one or more of R⁴, R⁵ and R⁶ represents ―COOH or -ACOOH, by selective hydrolysis of a compound of formula IV,

in which

R, E, X and G are as defined above,

one or more of D⁴, D⁵ and D⁶ represent a group hydrolysable to ―COOH, or to ―ACOOH, and the remainder of D⁴, D⁵ and D⁶ represent groups R⁴, R⁵ and R⁶ as defined above,

(b) reacting a compound of formula REZ with a compound of formula V or an ester thereof,

in which

R, E, G, R⁴, R⁵and R⁶ are as defined above, and

L and Z represent the pair of groups (i) hydrogen or a reactive metal, and (ii) a hydrocarbon chain having from 2 to 7 carbon atoms and carrying an anion forming group or an epoxide group,

(c) producing a compound of formula I in which one or more of R¹ to R⁶ represent an alkyl group containing at least 2 carbon atoms and/or A represents an ethylene chain, by hydrogenation of a compound of formula I wherein one or more of R¹ to R⁶ represents ·an alkenyl or alkanoyl group, and/or A represents -CH=CH-,

(d) producing a compound of formula I in which one or more of R⁴, R⁵ and R⁶ represent -ACOOH where A represents a group OY or SY, by reacting a corresponding compound of formula I in which either an adjacent pair of R¹, R² and R³ represent―OH and an alkanoyl group, or none of R¹, R² and R³ represents a non-hydrogen-bonded hydroxyl group and one of R⁴, R⁵ and R⁶ represents an ―OH or―SH group, with an appropriate haloalkanoic acid derivative in the presence of a suitable base,

e) production of a compound of formula I in which at least one of R¹, R² and R³ represents alkenyloxy or alkoxy, by alkenylating or alkylating a corresponding compound of formula I in which at least one of R¹, R² and R³ represents hydroxy,

f) production of a compound of formula I, or an ester thereof, in which at least one of R¹, R² and R³ represents ―OH and another of R¹, R² and R³ represents an-allyl group or an allyl group substituted by alkyl in the position adjacent to the benzene ring, by subjecting to an elevated temperature a corresponding compound offormula I, or an ester therefore, in which at least one of R¹, R² and R³ represents hydrogen and another of R¹, R² and R³ represents an allyloxy group or an alkyl substituted allyloxy group, or

g) converting an acid of formula I to a pharmaceutically acceptable derivative thereof or vice versa.

2. A process according to Claim 1, wherein each of R¹ to R⁶ when they contain carbon, contain less than 7 carbon atoms.

3. A process according to Claim 1 or 2, wherein one of R⁴, R⁵ and R⁶ is ―COOH or ―ACOOH para to the group G.

4. A process according to any one of the preceding claims, wherein X represents trimethylene or 2-hydroxytrimethylene.

5. A process according to any one of the preceding claims, wherein E and G are both oxygen or one is oxygen and the other is sulphur.

6. A process according to any one of the preceding claims, wherein E and G are both oxygen, one or more of R¹, R² and R³ represent alkyl, alkenyl, alkoxy, alkanoyl or hydroxy and the remainder each represent hydrogen, and X, R⁴, R⁵ and R⁶ are as defined in Claim 1 save that Y does not represent ―CH=CH―.

7. A process according to any one of the preceding claims, wherein E and G are both oxygen, R¹ represents alkanoyl C 2 to 4, R³ is -OH, R⁴ is ortho to G, R² and R⁴, which may be the same or different, each represent alkyl C 1 to 4, R⁵is hydrogen and R⁶ represents carboxy,―YCOOH or―OYCOOH in which Y does not represent -CH=CH-.

8. A process according to Claim 1, wherein the compound of formula I is of formula la,

in which

M is hydrogen or -OH,

A^a is ―SCH₂COOH, ―CH=CHCOOH or ―CH₂CH₂COOH, and

E^a is ―O― when A^a is ―SCH₂COOH or ―S― when A^a is -CH=CHCOOH or―CH₂CH₂COOH, or a pharmaceutically acceptable salt thereof.